man/systemd-detect-virt.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
   5
   6 <refentry id="systemd-detect-virt"
   7           xmlns:xi="http://www.w3.org/2001/XInclude">
   8
   9   <refentryinfo>
  10     <title>systemd-detect-virt</title>
  11     <productname>systemd</productname>
  12   </refentryinfo>
  13
  14   <refmeta>
  15     <refentrytitle>systemd-detect-virt</refentrytitle>
  16     <manvolnum>1</manvolnum>
  17   </refmeta>
  18
  19   <refnamediv>
  20     <refname>systemd-detect-virt</refname>
  21     <refpurpose>Detect execution in a virtualized environment</refpurpose>
  22   </refnamediv>
  23
  24   <refsynopsisdiv>
  25     <cmdsynopsis>
  26       <command>systemd-detect-virt</command>
  27       <arg choice="opt" rep="repeat">OPTIONS</arg>
  28     </cmdsynopsis>
  29   </refsynopsisdiv>
  30
  31   <refsect1>
  32     <title>Description</title>
  33
  34     <para><command>systemd-detect-virt</command> detects execution in
  35     a virtualized environment. It identifies the virtualization
  36     technology and can distinguish full machine virtualization from
  37     container virtualization. <filename>systemd-detect-virt</filename>
  38     exits with a return value of 0 (success) if a virtualization
  39     technology is detected, and non-zero (error) otherwise. By default,
  40     any type of virtualization is detected, and the options
  41     <option>--container</option> and <option>--vm</option> can be used
  42     to limit what types of virtualization are detected.</para>
  43
  44     <para>When executed without <option>--quiet</option> will print a
  45     short identifier for the detected virtualization technology. The
  46     following technologies are currently identified:</para>
  47
  48     <table>
  49       <title>Known virtualization technologies (both
  50       VM, i.e. full hardware virtualization,
  51       and container, i.e. shared kernel virtualization)</title>
  52       <tgroup cols='3' align='left' colsep='1' rowsep='1'>
  53         <colspec colname="type" />
  54         <colspec colname="id" />
  55         <colspec colname="product" />
  56         <thead>
  57           <row>
  58             <entry>Type</entry>
  59             <entry>ID</entry>
  60             <entry>Product</entry>
  61           </row>
  62         </thead>
  63         <tbody>
  64           <row>
  65             <entry valign="top" morerows="13">VM</entry>
  66             <entry><varname>qemu</varname></entry>
  67             <entry>QEMU software virtualization, without KVM</entry>
  68           </row>
  69
  70           <row>
  71             <entry><varname>kvm</varname></entry>
  72             <entry>Linux KVM kernel virtual machine, with whatever software, except Oracle Virtualbox</entry>
  73           </row>
  74
  75           <row>
  76             <entry><varname>zvm</varname></entry>
  77             <entry>s390 z/VM</entry>
  78           </row>
  79
  80           <row>
  81             <entry><varname>vmware</varname></entry>
  82             <entry>VMware Workstation or Server, and related products</entry>
  83           </row>
  84
  85           <row>
  86             <entry><varname>microsoft</varname></entry>
  87             <entry>Hyper-V, also known as Viridian or Windows Server Virtualization</entry>
  88           </row>
  89
  90           <row>
  91             <entry><varname>oracle</varname></entry>
  92             <entry>Oracle VM VirtualBox (historically marketed by innotek and Sun Microsystems), for legacy and KVM hypervisor</entry>
  93           </row>
  94
  95           <row>
  96             <entry><varname>powervm</varname></entry>
  97             <entry>IBM PowerVM hypervisor — comes as firmware with some IBM POWER servers</entry>
  98           </row>
  99
 100           <row>
 101             <entry><varname>xen</varname></entry>
 102             <entry>Xen hypervisor (only domU, not dom0)</entry>
 103           </row>
 104
 105           <row>
 106             <entry><varname>bochs</varname></entry>
 107             <entry>Bochs Emulator</entry>
 108           </row>
 109
 110           <row>
 111             <entry><varname>uml</varname></entry>
 112             <entry>User-mode Linux</entry>
 113           </row>
 114
 115           <row>
 116             <entry><varname>parallels</varname></entry>
 117             <entry>Parallels Desktop, Parallels Server</entry>
 118           </row>
 119
 120           <row>
 121             <entry><varname>bhyve</varname></entry>
 122             <entry>bhyve, FreeBSD hypervisor</entry>
 123           </row>
 124
 125           <row>
 126             <entry><varname>qnx</varname></entry>
 127             <entry>QNX hypervisor</entry>
 128           </row>
 129
 130           <row>
 131             <entry><varname>acrn</varname></entry>
 132             <entry><ulink url="https://projectacrn.org">ACRN hypervisor</ulink></entry>
 133           </row>
 134
 135           <row>
 136             <entry valign="top" morerows="9">Container</entry>
 137             <entry><varname>openvz</varname></entry>
 138             <entry>OpenVZ/Virtuozzo</entry>
 139           </row>
 140
 141           <row>
 142             <entry><varname>lxc</varname></entry>
 143             <entry>Linux container implementation by LXC</entry>
 144           </row>
 145
 146           <row>
 147             <entry><varname>lxc-libvirt</varname></entry>
 148             <entry>Linux container implementation by libvirt</entry>
 149           </row>
 150
 151           <row>
 152             <entry><varname>systemd-nspawn</varname></entry>
 153             <entry>systemd's minimal container implementation, see <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry></entry>
 154           </row>
 155
 156           <row>
 157             <entry><varname>docker</varname></entry>
 158             <entry>Docker container manager</entry>
 159           </row>
 160
 161           <row>
 162             <entry><varname>podman</varname></entry>
 163             <entry><ulink url="https://podman.io">Podman</ulink> container manager</entry>
 164           </row>
 165
 166           <row>
 167             <entry><varname>rkt</varname></entry>
 168             <entry>rkt app container runtime</entry>
 169           </row>
 170
 171           <row>
 172             <entry><varname>wsl</varname></entry>
 173             <entry><ulink url="https://docs.microsoft.com/en-us/windows/wsl/about">Windows Subsystem for Linux</ulink></entry>
 174           </row>
 175
 176           <row>
 177             <entry><varname>proot</varname></entry>
 178             <entry><ulink url="https://proot-me.github.io/">proot</ulink> userspace chroot/bind mount emulation</entry>
 179           </row>
 180
 181           <row>
 182             <entry><varname>pouch</varname></entry>
 183             <entry><ulink url="https://github.com/alibaba/pouch">Pouch</ulink> Container Engine</entry>
 184           </row>
 185         </tbody>
 186       </tgroup>
 187     </table>
 188
 189     <para>If multiple virtualization solutions are used, only the
 190     "innermost" is detected and identified. That means if both
 191     machine and container virtualization are used in
 192     conjunction, only the latter will be identified (unless
 193     <option>--vm</option> is passed).</para>
 194     <para> Windows Subsystem for Linux is not a Linux container,
 195     but an environment for running Linux userspace applications on
 196     top of the Windows kernel using a Linux-compatible interface.
 197     WSL is categorized as a container for practical purposes.
 198     Multiple WSL environments share the same kernel and services
 199     should generally behave like when being run in a container.</para>
 200   </refsect1>
 201
 202   <refsect1>
 203     <title>Options</title>
 204
 205     <para>The following options are understood:</para>
 206
 207     <variablelist>
 208       <varlistentry>
 209         <term><option>-c</option></term>
 210         <term><option>--container</option></term>
 211
 212         <listitem><para>Only detects container virtualization (i.e.
 213         shared kernel virtualization).</para></listitem>
 214       </varlistentry>
 215
 216       <varlistentry>
 217         <term><option>-v</option></term>
 218         <term><option>--vm</option></term>
 219
 220         <listitem><para>Only detects hardware virtualization.</para></listitem>
 221       </varlistentry>
 222
 223       <varlistentry>
 224         <term><option>-r</option></term>
 225         <term><option>--chroot</option></term>
 226
 227         <listitem><para>Detect whether invoked in a
 228         <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 229         environment. In this mode, no output is written, but the return
 230         value indicates whether the process was invoked in a
 231         <function>chroot()</function>
 232         environment or not.</para></listitem>
 233       </varlistentry>
 234
 235       <varlistentry>
 236         <term><option>--private-users</option></term>
 237
 238         <listitem><para>Detect whether invoked in a user namespace.  In this mode, no
 239         output is written, but the return value indicates whether the process was invoked
 240         inside of a user namespace or not. See
 241         <citerefentry project='man-pages'><refentrytitle>user_namespaces</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 242         for more information.</para></listitem>
 243       </varlistentry>
 244
 245       <varlistentry>
 246         <term><option>-q</option></term>
 247         <term><option>--quiet</option></term>
 248
 249         <listitem><para>Suppress output of the virtualization
 250         technology identifier.</para></listitem>
 251       </varlistentry>
 252
 253       <varlistentry>
 254         <term><option>--list</option></term>
 255
 256         <listitem><para>Output all currently known and detectable container and VM environments.</para></listitem>
 257       </varlistentry>
 258
 259       <xi:include href="standard-options.xml" xpointer="help" />
 260       <xi:include href="standard-options.xml" xpointer="version" />
 261     </variablelist>
 262
 263   </refsect1>
 264
 265   <refsect1>
 266     <title>Exit status</title>
 267
 268     <para>If a virtualization technology is detected, 0 is returned, a
 269     non-zero code otherwise.</para>
 270   </refsect1>
 271
 272   <refsect1>
 273     <title>See Also</title>
 274     <para>
 275       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 276       <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 277       <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
 278       <citerefentry project='man-pages'><refentrytitle>namespaces</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 279     </para>
 280   </refsect1>
 281
 282 </refentry>